I used to think weather icons were just little pictures.
Then I started paying attention to how they actually work—how a single curved line can mean “partly cloudy” in one app and “mostly sunny” in another, how three wavy lines universally signal rain but nobody can agree on what constitutes a “thunderstorm” versus just “rain with lightning.” The visual language of meteorological symbols turns out to be this fascinating mess of international standards, corporate branding decisions, and cultural assumptions about what weather even looks like. I’ve spent way too much time comparing weather apps on my phone, and honestly, the inconsistencies are kind of maddening once you notice them.
Anyway, the World Meteorological Organization has been trying to standardize these things since the 1950s, with varying degrees of success. Some symbols are genuinely universal—the sun is always a circle with rays, clouds are always puffy shapes—but the details splinter into chaos pretty quickly.
The geometry of precipitation and how designers choose to represent falling water
Here’s the thing about rain: it’s just lines falling downward, right? Except it’s not that simple. Some icon sets use straight lines, others use slightly curved ones to suggest wind. The number of lines matters too—three lines might mean light rain, five or six could indicate heavy rain, but there’s no actual standard for this. I guess it makes sense that designers would want flexibility, but it creates this weird situation where you’re constantly recalibrating your mental model depending on which app you’re using. Snowflakes are even worse, because everyone has a different idea of what a “stylized” snowflake should look like—six points, eight points, geometric versus organic, filled versus outlined.
The iPhone weather app uses a particular shade of blue for rain that’s become almost iconic, but Samsung’s default weather uses more of a gray-blue. These aren’t just aesthetic choices—they’re encoding information about severity and type that we absorb without thinking.
Why the sun keeps getting smaller and clouds keep getting more abstract over time
If you look at weather icons from the 1980s and 90s—the kind printed in newspapers or shown on TV news broadcasts—the sun is huge, often taking up half the frame, with these dramatic radiating lines. Modern weather icons have shrunk the sun down to maybe 30% of the icon space, sometimes even less. I think this reflects our shift toward mobile interfaces where clarity at small sizes matters more than dramatic visual impact. Clouds have gone through a similar transformation, moving from detailed, almost painterly renderings to these simplified geometric forms—two or three overlapping circles, basically. It’s efficient, sure, but something gets lost in the translation.
Turns out there’s actual research on this—a 2019 study from the University of Reading found that people interpret simplified weather icons faster but with slightly less accuracy than more detailed versions. The tradeoff is real.
The impossible task of visualizing “partly cloudy” versus “partly sunny” and why it maybe doesn’t matter
Wait—maybe the most absurd thing about weather iconography is that we have seperate symbols for “partly cloudy” and “partly sunny,” which are meteorologically identical conditions, just framed differently. Some apps show partly cloudy as a cloud with a small sun peeking out, while partly sunny is a sun with a small cloud in front. Other apps don’t bother distinguishing them at all, which honestly seems more rational. The National Weather Service officially defines partly sunny as applicable only during daylight hours with 3/8 to 5/8 cloud cover, but try explaining that to someone checking their phone at 6 AM trying to decide whether to bring an umbrella.
I’ve seen weather apps that use seven different cloud-sun combinations, and I genuinely can’t tell most of them apart without studying them closely.
Cultural differences in storm symbolism and the lightning bolt problem
Lightning bolts are almost always depicted as angular, zigzag shapes—that classic superhero-style bolt. But real lightning doesn’t usually look like that; it’s more branching and organic, with multiple fractal tendrils. The stylized version comes from heraldry and early electrical diagrams, and we’re just stuck with it now. What varies more across cultures is how storms themselves get categorized visually. Japanese weather icons often distinguish between different types of rain intensity with much more granularity than Western apps—they have specific symbols for “rain that might stop soon” versus “rain that’s settling in for the day,” which is incredibly useful information that English-language apps usually bury in text descriptions. Korean weather apps sometimes use red accents for heat-related warnings in ways that feel more urgent than the yellows and oranges common in American design.
There’s no universal symbol for “tropical storm” that doesn’t just look like regular rain to people unfamiliar with the convention.
The surprising durability of obsolete symbols and what that reveals about visual literacy
We still use thermometer icons for temperature despite most people under 30 never having used a mercury thermometer. The barometer symbol—that circular gauge with a needle—persists even though digital sensors replaced analog barometers decades ago. These visual fossils hang around because they’ve become abstract signifiers rather than literal representations, which is kind of how all language works eventually. I used to think this was just laziness, but it’s actually more interesting than that—it shows how visual symbols can outlive their referents and still function perfectly well. The windsock symbol for wind direction is another example; actual windsocks exist, sure, but they’re not exactly common in everyday experience anymore. Yet the symbol remains immediately readable, which suggests we’re recognizing the pattern rather than the object.
Honestly, this might be the most human thing about weather icons—they’re imperfect, inconsistent, sometimes illogical, but they mostly work anyway because we’re good at adapting to messy systems.
